If your running in the coin mode accept notch #3. This will give you a better beep on iffy nickels. Plus give you maybe (not scientific) a 25% more chance at a gold ring. In trashy sites or when I don't have much time I run my custom mode. That is simply the coin mode plus #3 notch or what I call high foil. Dig all those medium tones and see what you get. I know I get more nickels.